hey guys, i need help. my 97 2500 has lost all of its power. starts perfect runs good but is gutless. i can still hear the turbo spooling up; sounds the same and i cannot find any leaks in the intercooler/intake system. it also does not roll black smoke like it did before. just a little puff of grey on takeoff. i did the injector test where you loosen the lines and listen for an rpm drop and it did drop rpm noticeably on each one. also my fuel mileage has gone from about 20 to about 8-12. all of this happened within the last few weeks. i am not equipped to do much testing on this truck nor do i know very much about them, but if anyone has had symptoms like these i would love to know what the problem was and how it was repaired. also it has new fuel filter. thanks for any info yall can provide. jason

 

Check the line to the wastegate from the compressor housing. Might have line leak. AFC may be hanging up also.

 

The first thing to do is to measure the boost under load. Get a boost gauge and report back.

 

The timing may have slipped, pretty common issue if it has never been checked.Usually a boost leak will give you lots of black smoke due to lack of air.It is hard to know though with out a set of gauges to see what is going on.

 

if the timing slipped wouldn't it be hard to start? it acts like the throttle is not opening all the way or possibly not delivering as much fuel. you can take off at light to moderate throttle and it runs fine and accellerates ok but if you go from there to full throttle, it doesn't change ie: the rpms do not come up and no more fuel is sent to engine. if that makes any sense

 

did you mess with your afc housing? i turned mine the wrong way and it was totally balless

 

i messed with it some when i first got the truck 2 yrs ago and have had the bolts come loose on it a few times since but as far as turning it up or anything i have not done anything to it. this just started recently with out any changes on my part.

 

Check the diaphragm of the wastegate actuator for a leak. It's very common, and if it leaks, boost pressure won't get to the AFC to allow it to add fuel.

 

Check your intercooler boots. a leak will affect your performance.

 

Don't meant to hi-jack the thread, I can start my own if you would like, but;

I have a similar issue with my truck. I have 318k Miles, I have not had the timing checked, with the plate slid forward almost all the way I am building at max just under 20lbs of boost. Could this be a bad wastegate? I do not get much smoke at all. A little ammount of black smoke if I roll into the throttle with the TC locked, and a little puff right from the start but that is all.

One thing I haven't checked is I replaced my fuel shutoff solenoid about a year ago. If that is poorly/incorrectly adjusted could it affect performance?

Let me know what you all think. Thanks, Tim

 

If your wastegate actuator hasn't been re-adjusted or blocked off, it'll still open at whatever the factory setting was; generally 18-20 psi. Yes, if the shutoff solenoid is binding or misadjusted, it'll cause poor performance.